A water jet drilling construction system for vertical excavation and a construction method thereof

Abstract

The present application relates to the geological drilling technology field, especially to a kind of water mill drill construction system and construction method for vertical excavation, it includes double-channel rotary joint and multi-ring concentric cutterhead assembly, cutterhead assembly is coaxially set from inside to outside grouting sensing component and concentric circle drill component, center flow guide pipe is connected by elastic suspension mechanism, stretch forward when meeting soft soil resistance, mechanical misplacement is conducted to internal flow channel, and automatic injection consolidation slurry is automatically injected;When meeting hard rock resistance, locking grouting hole is retracted, simultaneously sliding flow channel distribution valve, high-pressure water is guided to push flow channel, and the radial clamping assembly of the inner wall of concentric drill cylinder is driven to pop out.Radial clamping assembly uses wedge-shaped inclined plane self-locking effect, and when pulling up, the gravity of rock mass is converted into clamping force, and the in-situ seizure of slag is realized.The present application uses pure physical displacement linkage, without setting downhole sensor and solenoid valve, realizes the continuous unmanned construction of soft rock automatic grouting, hard rock drill expansion clamping.

Description

Technical Field

[0001] This invention relates to the field of geological drilling technology, and in particular to a water-cooled drilling system and its construction method for vertical excavation. Background Technology

[0002] For pile foundation construction in mountainous areas, confined spaces, or special terrains where large drilling or perforation equipment cannot reach, the engineering community still primarily uses the manual excavation method for bored piles. Among these methods, vertical excavation using water-cooled drilling rigs offers significant advantages such as minimal environmental disturbance, low safety risks, and high-quality borehole formation, eliminating the need for blasting operations, and has been widely adopted in manually excavated bored pile projects. However, current conventional water-cooled drilling operations heavily rely on manual operation of the drilling rig for layered circular cutting and core sampling. This process is not only extremely labor-intensive, but also presents workers with significant safety risks within the confined space of deep holes, including the constant threat of soil and rock collapse, sudden releases of toxic gases from underground, and falling objects from the pile top. Consequently, the use of manually excavated bored piles is restricted or prohibited in many areas. To reduce the risks of human error and improve efficiency, in the existing publication number CN116971733A, which describes an integrated exploration and injection equipment and process suitable for tunneling in complex geological conditions, the supporting equipment for the integrated exploration and injection construction process is set up to avoid the problem of frequently changing and using multiple sets of equipment and the resulting equipment downtime.

[0003] While replacing manual drilling with small, intelligent equipment is theoretically feasible, existing vertical tunneling equipment still has many shortcomings in practical applications. Firstly, when encountering weak karst caves or collapsed areas, existing equipment typically requires first raising the drill string, then lowering a separate grouting pipe for consolidation and reinforcement, followed by switching equipment for drilling and cutting. After cutting out concentric rock rings, additional specialized mechanical grippers or wedges are needed for core sampling. Frequent equipment changes lead to inefficiency, and the judgment of grouting timing relies excessively on external sensors, which are prone to failure in the harsh drilling mud environment. Furthermore, to achieve multiple functions such as grouting, cooling and slag removal, and mechanical clamping, existing intelligent drilling tools require extremely complex internal hydraulic pipelines, electromagnetic directional valve assemblies, and multiple power sources, resulting in bulky equipment with a very high failure rate. This makes them unsuitable for the lightweight, modular assembly requirements of small-diameter, narrow manually excavated boreholes. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a water-cooled drilling system and its construction method for vertical tunneling.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A water-cooled drilling system for vertical tunneling includes a drill rod body for tunneling through soil layers. The drill rod body includes a power drive assembly disposed on its upper part for driving its rotation, and a cutterhead assembly disposed below its inner cavity. The cutterhead assembly includes a dual-channel rotary joint that is independently connected to high-pressure cooling water and consolidation grout, and a grouting sensing assembly and a concentric circular drill assembly coaxially sleeved from the inside to the outside. The grouting sensing assembly includes a guide pipe and a closed kit connected to the lower part of the guide pipe. A through hole is provided at the bottom center of the drill rod body for the axial passage of the guide pipe. A central cutting tooth is provided at the end of the guide pipe. The lower end of the dual-channel rotary joint is connected to the grouting channel in the inner cavity of the guide pipe. The guide pipe is axially controlled by drilling pressure to generate relative movement with the drill rod body, and cooperates with the closed kit to adaptively open and close the grouting channel. The concentric circular drill assembly includes a flow distribution valve disposed in the inner cavity of the drill rod body and a concentric cutting drill barrel fixed below the outer end of the drill rod body. The concentric cutting drill barrel is composed of a double-walled tube, and a vertical pushing flow channel is opened inside the tube wall. Radial clamping components communicating with the pushing flow channel are arrayed on the inner side wall of the lower end of the concentric cutting drill barrel. The flow distribution valve includes a valve core and a valve sleeve with an axial sliding assembly gap. The valve core is sleeved and fixed on the guide tube. The side wall of the valve core is provided with a side hole communicating with the water inlet flow channel of the inner cavity of the guide tube. The valve sleeve is provided with a vertical first connecting hole and a second connecting hole. The first connecting hole is guided to the concentric cutting drill barrel through the cooling flow channel of the side wall of the drill rod body. The second connecting hole communicates with the pushing flow channel inside the tube wall. The cutterhead assembly is configured to have two linkage states: when the central cutting tooth drills into the soft soil area, the central cutting tooth overcomes the formation resistance, and the sealing kit communicates with the grouting channel in the inner cavity of the guide pipe to introduce grout into the soft soil layer. At the same time, the side hole of the valve core is aligned with the first connecting hole to conduct cooling water to the concentric cutting drill barrel for slag removal and cooling. When the central cutting tooth drills into the hard rock area or cannot overcome the formation resistance, the guide pipe is obstructed and relatively retracts. The sealing kit is misaligned with the grouting channel in the inner cavity of the guide pipe to close, cutting off the grout input. At the same time, the side hole of the valve core is aligned with the second connecting hole to conduct cooling water to the pushing channel. The radial clamping assembly is pushed out by water pressure to clamp and remove the cut concentric rock ring.

[0006] Furthermore, the sealing kit includes a sealing sleeve, a first elastic component, and a limiting ring disposed at the lower end of the outer wall of the guide pipe. The first elastic component is sleeved on the guide pipe and abuts against the limiting ring and the drill pipe body. The sealing sleeve is disposed below the through hole, allowing the guide pipe to pass through its inner cavity. The sealing sleeve is fitted snugly with the guide pipe, and the side wall of the sealing sleeve is provided with a slurry drainage hole. When the central cutting tooth at the bottom of the guide pipe contacts soil media of different hardness, the formation reaction force will be transmitted to the limiting ring. The first elastic component acts as a buffer unit, and its deformation depends on the mechanical balance between the applied drill pressure and the formation bearing capacity. If the formation bearing capacity is small, the guide pipe remains extended under the combined action of the drill string weight and the preload of the first elastic component, exposing the slurry drainage hole. If the formation is hard, the increased end-face reaction force will force the limiting ring to compress the first elastic component upward, causing the guide pipe to undergo upward axial displacement within the through hole and the sealing sleeve. Automatic control of opening or closing of fluid pipelines is achieved through axial travel difference.

[0007] Furthermore, when the first elastic component is in a naturally extended or uncompressed state, the grouting channel communicates with the slurry discharge guide hole, and the side hole of the valve core communicates with the first connecting hole. When the first elastic component is at its compression limit, the grouting channel and the slurry discharge guide hole are misaligned and closed, and the side hole of the valve core communicates with the second connecting hole. In the extended state where the first elastic component is not compressed, the grouting channel is spatially aligned with the axial elevation of the slurry discharge guide hole, allowing the high-pressure consolidation grout to flow laterally and penetrate into the surrounding soft strata for pre-reinforcement. In this state, the side hole of the valve core inside the flow distribution valve is spatially aligned with the first connecting hole on the valve sleeve, allowing high-pressure cooling water to enter the cooling channel, ensuring continuous water supply to the concentric cutting drill barrel under conventional slag discharge and cooling mode. When encountering hard rock, causing the first elastic component to be compressed to its limit, the upward movement of the guide pipe causes the side hole of the grouting channel to slide into the non-perforated blind zone of the closed casing. The rigid fit of the metal wall cuts off the grout passage, preventing grout from being wasted or clogging the drill bit in the hard rock section. At the same time, the side hole of the valve core moves upward synchronously with the guide pipe, disengaging from the first connecting hole and sliding to the position of the second connecting hole, thereby transferring the kinetic energy of the high-pressure cooling water circuit to the pushing channel.

[0008] Furthermore, the initial preload and stiffness coefficient of the first elastic component are configured to be greater than the ultimate penetration resistance generated by conventional soft soil and silt formations on the central cutting tooth, ensuring that the first elastic component remains extended during drilling in soft soil, and less than the end-face bearing capacity generated by hard rock or highly compacted soil layers on the central cutting tooth, ensuring that the first elastic component is forcibly compressed when encountering hard formations. When traversing silt, loose sand, or karst cave filling materials, the downward thrust provided by the first elastic component is sufficient to overcome the frictional resistance of the guide pipe sliding along the through hole and the end-face resistance of the formation, keeping the grouting channel continuously unobstructed. At the same time, the upper limit of its stiffness coefficient is calibrated with reference to the uniaxial compressive strength of moderately weathered or slightly weathered rock, ensuring that once the central cutting tooth touches the hard parent rock requiring hard rock clamping and breaking, the formation can provide sufficient normal reaction force to compress the first elastic component, preventing the guide pipe from undergoing rigid buckling deformation due to excessive stiffness of the first elastic component or causing the drilling pressure to be ineffectively transferred to the outer concentric cutting drill barrel.

[0009] Furthermore, the upper end of the guide pipe is connected to a dual-channel rotary joint via a sleeve telescopic pipe. The grouting channel and the water inlet channel are respectively connected to the external solidification grout and high-pressure cooling water through independent sealed pipelines. The inner wall of the telescopic pipe is equipped with multiple high-pressure resistant dynamic sealing rings, which maintain the airtightness of the fluid transmission channel while the guide pipe floats up and down and changes direction. The grouting channel and the water inlet channel are isolated. Through the architecture of the dual-channel rotary joint and the internal coaxial double-layer or parallel independent sealed pipelines, the independent transmission of high-pressure, high-flow-rate cooling and cleaning media and high-viscosity grouting and solidification media at the rotary joint is ensured.

[0010] Furthermore, a driving hydraulic chamber is connected to the bottom of the push flow channel facing the central cutting tooth. The radial clamping assembly is horizontally slidably connected to the driving hydraulic chamber via a transverse guide groove. One end of the driving hydraulic chamber is connected to the push flow channel, and the other end is connected to the outside. The radial clamping assembly vertically closes the driving hydraulic chamber, and limit clamps are provided at both ends of the guide groove. When high-pressure water is filled through the push flow channel, the hydrostatic pressure of the fluid acts directly on the inner end face of the radial clamping assembly, pushing it outward laterally as a hydraulic piston. The guide groove provides a horizontal guiding constraint, ensuring that the movement trajectory of the clamping assembly is always perpendicular to the axis of the concentric cutting drill barrel. The limit clamps on both sides limit the maximum extension stroke of the radial clamping assembly, preventing it from being flushed out of the pipe wall and falling off when under pressure without a core sample.

[0011] Furthermore, the radial clamping assembly includes a movable plate and a top clamping plate, which slide together via opposing wedge-shaped inclined surfaces. The movable plate has a limiting groove containing a second elastic component. The top clamping plate has a limiting block embedded in the limiting groove on its side facing the movable plate. The second elastic component is positioned below the limiting block to push the top clamping plate upwards relative to the movable plate. The movable plate is directly pushed outwards by the water pressure of the driving hydraulic chamber, while the top clamping plate directly contacts and compresses the rock. The opposing wedge-shaped inclined surfaces between them cause the top clamping plate to generate an outward normal expansion thrust when it undergoes downward relative displacement with respect to the movable plate. The tenon-and-mortise nesting of the limiting groove and the limiting block provides a relative sliding guide while preventing the top clamping plate from rotating circumferentially or falling off. The second elastic component is positioned below the limiting top block. Before the clamping action occurs or during the no-load release phase, it continuously provides an upward lifting force, ensuring that the top of the clamping plate is at the same level as the top of the movable plate. When entering the clamping and slag removal process, and the clamping plate is dragged downward by the downward gravity of the rock ring, the clamping plate overcomes the elastic force of the second elastic component and slides downward, completing the conversion from fluid thrust to gravity self-locking clamping force.

[0012] Furthermore, the top clamping plate is provided with several anti-slip hard teeth on its side facing the central cutting tooth for gripping the rock. The upper end of the movable plate is also provided with a horizontal drainage cavity for pressure relief. This horizontal drainage cavity is connected to the outside when the second elastic component is compressed to its limit position. When the movable plate is pushed outward by water pressure, the anti-slip hard teeth utilize the local stress generated by the high pressure to pierce and destroy the mud skin and weathered layer on the surface of the rock ring, anchoring into the intact bedrock to establish an initial mechanical engagement fulcrum and increase the equivalent friction coefficient of the contact surface. Simultaneously, when the reaction forces of the rock ring's gravity and the top tension cause the top clamping plate to slide downward to its limit, the horizontal drainage cavity connects to the external annular space, discharging the high-pressure water accumulated in the driving hydraulic chamber to reduce pressure. On the one hand, it prevents the concentric cutting drill pipe wall from cracking due to the continuous increase of system water pressure. On the other hand, after the slag is discharged and the rock block is lifted to the ground, the back pressure resistance is discharged through the pressure relief hole, so that the movable plate can be smoothly retracted into the pipe wall under the second elastic component or manual knocking, thereby releasing the anchoring of the anti-slip hard teeth to the rock and ensuring the normal progress of the slag discharge and unloading process.

[0013] Furthermore, the system includes a detachable platform, a lifting casing frame, and a separate hydraulic power mechanism installed at the wellhead. The detachable platform spans across the wellhead, and the lifting casing frame slides up and down along the vertical guide rails of the detachable platform. The power drive assembly is mounted on the lifting casing frame and driven by the separate hydraulic power mechanism, applying drilling pressure or lifting tension to the drill pipe body below through the lifting and lowering motion of the lifting casing frame. The detachable platform is a modular steel structure connected by high-strength bolts, which can be quickly disassembled into small, lightweight units for easy manual transport into narrow wellhead areas in mountainous regions or densely built-up areas that are difficult for mechanical equipment to access. Its arrangement across the wellhead not only ensures the centering of the drill string but also distributes the huge reverse torque generated during drilling to the stable strata around the wellhead. The lifting casing frame and the vertical guide rail are connected by a roller or slider mechanism, eliminating radial sway and shaking of the drill pipe during high-speed rotation and ensuring the verticality of deep hole excavation. The split-type hydraulic power mechanism is connected to the power drive assembly via flexible high-pressure oil pipes, keeping vibration and noise sources away from the wellhead. The power drive assembly descends in a controlled manner along the guide rails as the casing frame rises, converting the equipment's own weight and the thrust output from the hydraulic cylinders into cutting pressure. During the slag removal stage, the casing frame is pulled upwards by cylinders or winches, providing sufficient vertical upward pulling force for breaking off and lifting the heavy concentric rock sheaths in the borehole.

[0014] A construction method for a water-cooled drilling system for vertical tunneling includes the following steps: S1: Assemble the modular detachable platform and install the drill pipe body above the wellhead, while connecting the external high-pressure cooling water and consolidation slurry to the dual-channel rotary joint, and lower the drill pipe body; S2: During the lowering process, the power drive component applies drilling pressure downwards. The concentric cutting drill barrel and the central cutting tooth contact the formation. Based on the hardness of the formation rock and soil, the magnitude of the reaction force at the end face of the central cutting tooth causes the guide pipe to generate relative axial displacement, thereby automatically controlling the opening and closing of the grouting channel. S3: At the same time, the guide pipe drives the valve core to generate relative displacement according to the difference in hardness of the soil and rock in the stratum, and automatically controls the high-pressure cooling water to enter the cooling channel or push the channel. S4: After cutting to the predetermined depth or encountering resistance that prevents further progress, the drill rod stops rotating and rises. At this point, the radial clamping assembly abuts against the concentric rock ring, using the lifting force of the drill rod body to hard-split it from the bottom bedrock. The friction between the abutting surface and the concentric rock ring holds and drives the concentric rock ring to rise until it is pulled out to the ground for slag removal, and the excavation is repeated.

[0015] In a construction method, in step S2 above, when the guide pipe is pushed forward by the first elastic component when it touches a low-resistance area of ​​soft rock or karst cave collapse, the sealing kit and the grouting channel inside the guide pipe are connected, and the consolidation grout in the grouting channel is automatically injected into the soil layer; when the guide pipe is pressed to the extreme state of hard rock or soft rock, causing the end face bearing capacity to exceed the spring preload threshold, the guide pipe is pushed back until the sealing kit and the grouting channel inside the guide pipe are misaligned and sealed, and the injection of consolidation grout stops.

[0016] In one construction method, in step S3 above, after the high-pressure cooling water enters the cooling channel, it flows to the end face of the concentric cutting drill barrel for slag removal and cooling; after the high-pressure cooling water enters the pushing channel, the high-pressure cooling water pushes the radial clamping assembly to radially clamp the cut independent concentric rock rings.

[0017] In one construction method, in step S4 above, the clamping force process of the rising drill rod body pulling out the concentric rock ring is as follows: after the radial clamping assembly is pushed out by high-pressure cooling water to initially engage the rock ring, when the drill rod body is lifted upward, the concentric rock ring will have a relative downward tendency due to its own weight. This downward tendency will cause the radial clamping assembly to be subjected to a downward pulling force. By utilizing the friction force generated by the contact surface, the axial gravity is converted into an inward squeezing radial clamping force, thereby ensuring that the concentric rock ring does not fall off during the deep hole lifting process.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention combines the guide pipe and the central cutting tooth into a movable sensing component. When the drill bit is lowered and encounters soft soil or karst caves without resistance, the guide pipe is initially extended by the combined action of the pre-tightening force of the first elastic component and gravity. The central cutting tooth and the concentric cutting drill barrel descend synchronously, and the slurry discharge guide hole and the grouting channel remain connected. Slurry is automatically injected for pre-consolidation. When encountering hard rock and the resistance increases, the guide pipe is pushed back. After the sealing kit and the grouting channel are misaligned and locked, the valve core is connected to the second connecting hole and guides the cooling water into the push channel. At this time, the valve core and the cooling channel are misaligned and closed. No electronic sensor or manual intervention is required, eliminating the cumbersome process of frequently raising and lowering the drill bit and greatly improving the tunneling efficiency in complex strata. 2. This invention transforms the concentric cutting drill barrel into a lifting clamp. When the system switches to the push flow channel, the high-pressure cooling water drives the movable plate and the top clamping plate to radially eject and engage the rock ring. When the slag is lifted upwards, the downward tendency of the concentric rock ring due to its own weight will force the top clamping plate to slide downwards along the wedge-shaped slope. By utilizing the mechanical wedge self-locking effect, the axial gravity of the rock ring and the mechanical lifting force are transformed into radial clamping force that squeezes inwards, overcoming the tensile and folding yield limit of the rock mass and hard-splitting and breaking it apart, while reducing the risk of slippage during heavy-load lifting. 3. This invention uses the obstructed displacement of the central guide pipe as a hydraulic reversing switch. It uses only high-pressure cooling water and slurry introduced through dual channels to automatically switch between slag discharge cooling and radial clamping and splitting by mechanical misalignment. It eliminates the need for electromagnetic reversing valves, independent hydraulic circuits and complex control harnesses, thereby reducing costs and the failure rate of electrical control equipment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the construction plan structure of the present invention; Figure 2 This is a partial planar structural diagram of the drill pipe body; Figure 3 This is a partial schematic diagram showing the grouting flow channel. Figure 4 This is a partial schematic diagram showing the grouting channel being blocked and retracted to close. Figure 5 This is a schematic diagram of the planar structure of the driving hydraulic chamber; Figure 6 This is a planar schematic diagram of the radial clamping assembly being pushed out by high-pressure cooling water; Figure 7 This is a schematic diagram of the disassembled structure of the radial clamping component; Figure labels: 1-Drill pipe body, 2-Dual-channel rotary joint, 3-Guide pipe, 4-Sealing kit, 401-Sealing sleeve, 402-First elastic component, 403-Limiting ring, 5-Through hole, 6-Central cutting tooth, 7-Grouting channel, 8-Channel distribution valve, 801-Valve core, 802-Valve sleeve, 9-Concentric cutting drill barrel, 10-Pushing channel, 11-Radial clamping assembly, 1101-Moving plate, 1102 - Tightening plate, 1103 - Limiting slide groove, 1104 - Second elastic component, 1105 - Limiting top block, 12 - Water inlet channel, 13 - First connecting hole, 14 - Second connecting hole, 15 - Cooling channel, 16 - Slurry discharge guide hole, 17 - Sleeve telescopic pipe, 18 - Driving hydraulic cavity, 19 - Guide groove, 20 - Limiting clip, 21 - Anti-slip hard teeth, 22 - Horizontal drainage cavity, 23 - Soil layer, 24 - Concentric rock ring. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0021] Example 1, as Figures 1-7As shown, the present invention discloses a water-cooled drilling system for vertical tunneling, including a drill rod body 1 for tunneling through soil layer 23. The drill rod body 1 includes a power drive assembly disposed on its upper part for driving its rotation, and a cutterhead assembly disposed below its inner cavity. The cutterhead assembly includes a dual-channel rotary joint 2 that is independently connected to high-pressure cooling water and consolidation slurry, and a grouting sensing assembly and a concentric circular drill assembly coaxially sleeved from the inside to the outside. The grouting sensing assembly includes a guide pipe 3 and a sealing kit 4 connected to the lower part of the guide pipe 3. A through hole 5 is provided at the bottom center of the drill rod body 1 for the guide pipe 3 to pass through axially. A central cutting tooth 6 is provided at the end of the guide pipe 3. The lower end of the dual-channel rotary joint 2 is connected to the grouting channel 7 in the inner cavity of the guide pipe 3. The guide pipe 3 is axially controlled by drilling pressure to generate relative movement with the drill rod body 1, and cooperates with the sealing kit 4 to adaptively open and close the grouting channel 7. The concentric circular drill assembly includes a flow channel distribution valve 8 disposed in the inner cavity of the drill rod body 1 and a concentric cutting drill cylinder 9 fixed below the outer end of the drill rod body 1. The concentric cutting drill cylinder 9 is composed of a double-layer tube wall, and a vertical push flow channel 10 is opened inside the tube wall. A radial clamping assembly 11 communicating with the push flow channel 10 is arrayed on the inner side wall of the lower end of the concentric cutting drill cylinder 9. The flow channel distribution valve 8 includes a valve core 801 and a valve sleeve 802 with an axial sliding assembly gap. The valve core 801 is sleeved and fixed on the guide pipe 3. The side wall of the valve core 801 is provided with a side hole communicating with the water inlet flow channel 12 in the inner cavity of the guide pipe 3. The valve sleeve 802 is provided with a vertical first connecting hole 13 and a second connecting hole 14. The first connecting hole 13 is guided to the concentric cutting drill cylinder 9 through the cooling flow channel 15 on the side wall of the drill rod body 1. The second connecting hole 14 is communicating with the push flow channel 10 in the tube wall. The cutterhead assembly is configured to have two linkage states: when the central cutting tooth 6 drills into the soft soil area, the central cutting tooth 6 overcomes the formation resistance, and the sealing kit 4 is connected to the grouting channel 7 inside the guide pipe 3 to introduce grout into the soft soil layer. At the same time, the side hole of the valve core 801 is aligned and connected with the first connecting hole 13 to guide cooling water to the concentric cutting drill barrel 9 for slag removal and cooling. When the central cutting tooth 6 drills into the hard rock area or cannot overcome the formation resistance, the guide pipe 3 is blocked and relatively retracts. The sealing kit 4 is misaligned and closed with the grouting channel 7 inside the guide pipe 3, cutting off the grout input. At the same time, the side hole of the valve core 801 is aligned and connected with the second connecting hole 14 to guide cooling water to the pushing channel 10, and the radial clamping assembly 11 is pushed out by water pressure to clamp and remove the cut concentric rock ring 24.

[0022] The sealing kit 4 includes a sealing sleeve 401, a first elastic component 402, and a limiting ring 403 disposed at the lower end of the outer wall of the guide pipe 3. The first elastic component 402 is sleeved on the guide pipe 3 and abuts against the limiting ring 403 and the drill pipe body 1. The sealing sleeve 401 is disposed below the through hole 5 and allows the guide pipe 3 to pass through its inner cavity. The inner wall of the sealing sleeve 401 is slidably fitted with the outer wall of the guide pipe 3. The side wall of the sealing sleeve 401 is provided with a slurry discharge guide hole 16. Specifically, when the central cutting tooth 6 at the bottom of the guide pipe 3 contacts the soil layer 23 medium of different hardness, the formation reaction force will be transmitted to the limiting ring 403. The first elastic component 402, as an energy storage and buffer unit, has a deformation that depends on the mechanical balance between the applied drilling pressure and the formation bearing capacity. If the stratum has low bearing capacity (soft soil or soft rock), the guide pipe 3 remains extended under the combined action of the drill bit's weight and the preload of the first elastic component 402, exposing the slurry discharge guide hole 16. If the stratum is hard (hard rock or compacted soft soil), the increased end-face reaction force will force the limiting ring 403 to compress the first elastic component 402 upwards, causing the guide pipe 3 to undergo upward axial displacement within the through hole 5 and the closed sleeve 401. Through the axial travel difference, automatic control of the fluid pipeline opening or closing is achieved, avoiding the failure of electronic sensors in complex underground mud environments and improving the operational reliability of the equipment under complex geological conditions.

[0023] When the first elastic component 402 is in a naturally extended or uncompressed state, the grouting channel 7 is connected to the slurry discharge guide hole 16, and the side hole of the valve core 801 is connected to the first connecting hole 13. When the first elastic component 402 is at its compression limit, the grouting channel 7 is misaligned and closed with the slurry discharge guide hole 16, and the side hole of the valve core 801 is connected to the second connecting hole 14. Specifically, in the extended state where the first elastic component 402 is not compressed, the grouting channel 7 is aligned with the axial elevation of the slurry discharge guide hole 16 in space, allowing the high-pressure consolidation grout to flow laterally and penetrate into the surrounding soft strata for pre-reinforcement. In this state, the side hole of the valve core 801 inside the flow distribution valve 8 is spatially aligned with the first connecting hole 13 on the valve sleeve 802, allowing high-pressure cooling water to enter the cooling channel 15, ensuring continuous water supply to the concentric cutting drill barrel 9 in the conventional slag discharge and cooling mode. When encountering hard rock, causing the first elastic component 402 to be compressed to its limit, the upward movement of the guide pipe 3 causes the side hole of the grouting channel 7 to slide into the non-perforated blind zone of the closed sleeve 401. The rigid fit of the metal wall cuts off the grout passage, preventing the grout from being wasted ineffectively in the hard rock section or clogging the drill bit. At the same time, the side hole of the valve core 801 moves upward synchronously with the guide pipe 3, disengaging from the first connecting hole 13 and sliding to the position of the second connecting hole 14. This instantly transfers the kinetic energy of the high-pressure cooling water circuit to the pushing channel 10. The simultaneous mechanical switching of the two fluids is completed using a single displacement trigger source, ensuring the directional output of the fluid under different geological conditions.

[0024] The initial preload and stiffness coefficient of the first elastic component 402 are configured such that they are greater than the ultimate penetration resistance generated by conventional soft soil and silt strata on the central cutting tooth 6, so that the first elastic component 402 remains extended during drilling in soft soil, and less than the end face bearing capacity generated by hard rock or highly dense soil layer 23 on the central cutting tooth 6, so that the first elastic component 402 is forcibly compressed when encountering hard strata. Specifically, the initial preload is set based on the undrained shear strength of the soft strata obtained from the field survey, ensuring that when crossing silt, loose sand or karst cave filling, the downward thrust provided by the first elastic component 402 is sufficient to overcome the frictional resistance of the guide pipe 3 sliding along the through hole 5 and the end face resistance of the strata, so that the grouting channel 7 remains continuously unobstructed. Meanwhile, the upper limit of its stiffness coefficient is calibrated with reference to the uniaxial compressive strength of moderately or slightly weathered rocks, ensuring that once the central cutting tooth 6 touches the hard parent rock requiring hard rock clamping and breaking, the formation can quickly provide sufficient normal reaction force to compress the first elastic component 402, preventing the guide pipe 3 from undergoing rigid buckling deformation due to excessive stiffness of the first elastic component 402 or causing the drilling pressure to be ineffectively transferred to the outer concentric cutting drill barrel 9. The stiffness range set based on the rock mechanics properties allows the drill bit to achieve autonomous adjustment and smooth transition between soft rock and hard rock excavation modes by relying on the changes in inherent reaction force during drilling, without relying on manual operation adjustments.

[0025] The upper end of the guide pipe 3 is connected to the dual-channel rotary joint 2 via a sleeve telescopic pipe 17. The grouting channel 7 and the water inlet channel 12 are respectively connected to the external solidification grout and high-pressure cooling water through independent sealed pipelines. Specifically, the inner wall of the telescopic pipe is equipped with multiple high-pressure resistant dynamic sealing rings, which maintain the airtightness of the fluid transmission channel while the guide pipe 3 floats up and down and changes direction. The grouting channel 7 is isolated from the water inlet channel 12. Through the dual-channel rotary joint 2 and the internal coaxial double-layer or parallel independent sealed pipeline structure, the independent transmission of high-pressure, high-flow-rate cooling and cleaning medium and high-viscosity grouting and solidification medium at the rotary joint is ensured. Preferably, the upper end of the guide pipe 3 is connected to the dual-channel rotary joint 2 via a sleeve telescopic pipe 17, and the grouting channel 7 and the water inlet channel 12 are respectively connected to the external solidification grout and high-pressure cooling water through independent sealed pipelines. The telescopic sleeve 17 adopts a coaxial double-wall nested sliding structure. Its central inner tube is rigidly fixed to the central grouting hole of the double-channel rotary joint 2 and is deeply inserted into the grouting channel 7 in the center of the inner cavity of the guide pipe 3. Its outer annular sleeve is connected to the outer annular cooling water hole of the double-channel rotary joint 2 and is slidably sleeved at the inlet of the water inlet channel 12 formed by the upper outer wall of the guide pipe 3. The inner wall of the telescopic sleeve and the outer wall of the central inner tube are equipped with multiple high-pressure resistant dynamic sealing rings, so that the guide pipe 3, while floating up and down due to the resistance of the formation, always slides along the central inner tube and the outer annular sleeve, thereby maintaining the airtightness of the fluid transmission channel throughout the entire axial stroke. The grouting channel 7 and the water inlet channel 12 are physically isolated by the pipe wall of the telescopic sleeve 17. Through the architecture of the double-channel rotary joint 2 and the internal coaxial double-layer or parallel independent sealing pipeline, the independent transmission of cooling cleaning medium and grouting consolidation medium at the rotary joint and the axial telescopic section is ensured.

[0026] The bottom of the push flow channel 10, facing the central cutting tooth 6, is connected to a driving hydraulic chamber 18. The radial clamping assembly 11 is horizontally slidably connected to the driving hydraulic chamber 18 via a transverse guide groove 19. One end of the driving hydraulic chamber 18 is connected to the push flow channel 10, and the other end is connected to the outside. The radial clamping assembly 11 vertically closes the driving hydraulic chamber 18. Both ends of the guide groove 19 are provided with limit clamps 20. Specifically, when high-pressure water is filled through the push flow channel 10, the hydrostatic pressure of the fluid acts directly on the inner end face of the radial clamping assembly 11, pushing it outward laterally as a hydraulic piston. The guide groove 19 provides a horizontal guiding constraint, ensuring that the movement trajectory of the clamping assembly is always perpendicular to the axis of the concentric cutting drill barrel 9. The limit clamps 20 on both sides limit the maximum extension stroke of the radial clamping assembly 11, preventing it from being flushed out of the pipe wall and falling off when under pressure without a core sample. Preferably, a spring mechanism for supporting the movable plate 1101 is also provided on the guide groove 19. The spring mechanism is located on the side of the movable plate 1101 facing the pushing channel 10. One end of the spring mechanism is fixedly connected to the surface of the movable plate 1101, and the other end is fixedly connected to the left end of the guide groove 19. This ensures that the movable plate 1101 is at the left end of the driving hydraulic cavity 18 when not subjected to external force. The length of the limiting slide groove 1103 and the second elastic component 1104 is arranged to adapt to the sinking depth of the pressing plate 1102. A mud-proof sealing baffle is provided on the open end face of the driving hydraulic cavity 18. The mud-proof sealing baffle can be fastened to the open end of the driving hydraulic cavity 18, similar to a cover. When the movable plate 1101 moves to the right and pushes out, the mud-proof sealing baffle is pushed out simultaneously, causing the mud-proof sealing baffle to fall into the soil layer.

[0027] The radial clamping assembly 11 includes a movable plate 1101 and a top clamping plate 1102. The movable plate 1101 and the top clamping plate 1102 are slidably engaged by opposing wedge-shaped inclined surfaces. The movable plate 1101 is provided with a limiting groove 1103, and a second elastic component 1104 is provided in the limiting groove 1103. The top clamping plate 1102 has a limiting top block 1105 embedded in the limiting groove 1103 on the side facing the movable plate 1101. The second elastic component 1104 is located below the limiting top block 1105 to push the top clamping plate 1102 upward relative to the movable plate 1101. Specifically, the movable plate 1101 is directly pushed outward by the water pressure of the driving hydraulic chamber 18, while the top clamping plate 1102 is used to directly contact and compress the rock. The top clamping plate 1102 has a slope thickness that narrows from top to bottom. The opposing wedge-shaped slopes between the top clamping plate 1102 and the movable plate 1101 generate an outward normal expansion thrust when the top clamping plate 1102 moves downward relative to the movable plate 1101. The tenon-and-mortise nesting of the limiting slide groove 1103 and the limiting top block 1105 provides a relative sliding guide while preventing the top clamping plate 1102 from rotating circumferentially or falling off. The second elastic component 1104 is disposed below the limiting top block 1105 and continuously provides an upward lifting force before the clamping action occurs, so that the top of the top clamping plate 1102 is at the same level as the top of the movable plate 1101. When entering the clamping and slag removal process, and the top clamping plate 1102 is dragged downward by the downward gravity of the rock ring, the top clamping plate 1102 overcomes the elastic force of the second elastic component 1104 and slides downward, completing the conversion from fluid thrust to gravity self-locking clamping force.

[0028] The top clamping plate 1102 is provided with several anti-slip hard teeth 21 on the side facing the central cutting tooth 6 for biting the rock. The upper end of the movable plate 1101 is also provided with a horizontal drainage cavity 22 for pressure relief. The horizontal drainage cavity 22 is connected to the outside when the second elastic component 1104 is compressed to the limit position. Specifically, when the movable plate 1101 is pushed outward by water pressure, the anti-slip hard teeth 21 use the strong local stress generated by the high pressure to pierce and destroy the mud skin and weathered layer on the surface of the rock ring, anchor into the intact bedrock, establish the initial mechanical biting fulcrum, and increase the equivalent friction coefficient of the contact surface. At the same time, when the reaction force of the rock ring gravity and the top tension causes the top clamping plate 1102 to slide downward to the limit (i.e., the second elastic component 1104 is compressed to the limit value), the horizontal drainage cavity 22 is connected to the external annulus, and the high pressure water accumulated in the driving hydraulic cavity 18 is discharged to reduce the pressure. On the one hand, this prevents the concentric cutting drill barrel 9 from cracking due to continuous increase in system water pressure. On the other hand, after the slag is discharged and the rock block is lifted to the ground, the back pressure resistance is released through the pressure relief hole, allowing the top clamping plate 1102 to move upward and reset under the action of the second elastic component 1104. This allows the movable plate 1101 to smoothly retract into the drive hydraulic chamber 18 under manual tapping, thereby releasing the anchoring of the anti-slip hard teeth 21 to the rock and ensuring the normal progress of the slag discharge and unloading process. Preferably, due to the bending loss of the high-pressure cooling water in the drive hydraulic chamber 18, its pressure has been reduced. When the high-pressure cooling water can be sprayed out from the horizontal drainage cavity 22, it indicates that the top clamping plate 1102 has moved downward. At this time, the clamping and fixing effect of the concentric rock ring 24 has been completed. Even if the upper side wall of the concentric rock ring 24 is impacted, it can still be guaranteed that the concentric rock ring 24 can be smoothly lifted and moved out.

[0029] It also includes a detachable platform, a lifting casing frame, and a separate hydraulic power mechanism installed at the wellhead. The detachable platform spans across the wellhead, and the lifting casing frame slides up and down along the vertical guide rail of the detachable platform. The power drive assembly is mounted on the lifting casing frame and driven by the separate hydraulic power mechanism, applying drilling pressure or lifting tension to the drill pipe body 1 below through the lifting and lowering action of the lifting casing frame. Specifically, the detachable platform adopts a modular steel structure connected by high-strength bolts, which can be quickly disassembled into small, lightweight units to facilitate manual transport into narrow wellhead sites in mountainous areas or densely built-up areas that are difficult for mechanical equipment to access. Its arrangement across the wellhead not only ensures the centering of the drill string but also distributes the huge reverse torque generated during drilling to the stable strata around the wellhead. The lifting casing frame and the vertical guide rail are engaged by a roller or slider mechanism, eliminating radial sway and shaking of the drill pipe during high-speed rotation and ensuring the verticality of deep hole excavation. The split-type hydraulic power mechanism is connected to the power drive assembly via flexible high-pressure oil pipes, keeping vibration and noise sources away from the wellhead. The power drive assembly descends in a controlled manner along the guide rails as the casing frame rises, converting the equipment's own weight and the thrust output from the hydraulic cylinders into cutting pressure. During the slag removal stage, the casing frame is pulled upwards by cylinders or winches, providing sufficient vertical upward pulling force for breaking and lifting the heavy concentric rock annulus 24 in the borehole.

[0030] Example 2, based on Example 1, proposes a construction method for a water-cooled drilling system for vertical tunneling, including the following steps: S1: Assemble the modular detachable platform above the wellhead and connect the power drive assembly and drill pipe body 1. Then connect the high-pressure water pipe of the external high-pressure water pump and the slurry pipe of the grouting pump to the corresponding inlet end of the dual-channel rotary joint 2 respectively. Start the lifting casing frame and vertically lower the drill pipe body 1, which is equipped with the cutterhead assembly, to the bottom of the hole to be excavated.

[0031] S2: During the lowering process, the hydraulic power mechanism drives the power drive assembly to rotate and apply continuous cutting pressure downwards. The concentric cutting drill barrel 9 and the central cutting tooth 6 at the bottom of the cutterhead assembly synchronously contact the formation and perform rotary cutting with the central cutting tooth 6 as the axis. At this time, the system automatically completes the identification of soft and hard formations by relying on the normal reaction force generated by the drill bit contacting the rock and soil end face of the formation. Then, through the compression or release of the relative axial slippage generated by the first elastic component 402 through the guide pipe 3, it controls the misalignment and locking or alignment and conduction of the side hole of the grouting channel 7 and the grout discharge guide hole 16.

[0032] S3: While performing step S2, the axial displacement of the guide pipe 3 synchronously drives the valve core 801 sleeved on it to generate a follow-up displacement. By using the mechanical sliding clearance, the orifice connection relationship inside the flow distribution valve 8 is changed, and the high-pressure cooling water delivered through the dual-channel rotary joint 2 is automatically controlled to enter the cooling flow channel 15 corresponding to the first connecting hole 13, or enter the push flow channel 10 corresponding to the second connecting hole 14.

[0033] S4: When the concentric cutting drill barrel 9 cuts to form an annular groove to a predetermined depth, or when the formation is so hard that the drilling resistance reaches the upper limit of the equipment's rated torque and cannot continue, the side hole of the valve core 801 is misaligned and closed with the open cooling channel at the bottom, and instantly aligns and connects with the closed second connecting hole 14 and the push flow channel 10. Because the fluid passage instantly switches from low-resistance direct discharge to pressurizing the closed drive hydraulic chamber 18, it will cause a violent water hammer effect in the water pressure in the ground high-pressure water pump pipeline. The system uses the sudden water pressure jump captured by the surface water pump pressure gauge as a judgment signal that the physical system has completed the internal blind switching. Subsequently, the lifting casing frame is slowly raised along the vertical guide rail, applying a lifting force to the drill rod body 1. At the instant the drilling rig stops rotating, the surface water pump maintains high-pressure water supply, and the high-pressure cooling water flows into the drive hydraulic chamber 18 in full through the connected push flow channel 10. High-pressure hydrostatic pressure acts directly on the inner side of the movable plate 1101, overcoming the initial preload of the second elastic component 1104 and driving the radial clamping component 11 to eject radially towards the core along the guide groove 19. The anti-slip hard teeth 21 on the surface of the top clamping plate 1102 are forcibly pressed into the sidewall of the independently cut concentric rock ring 24 by the high-pressure water, completing the initial mechanical engagement and anchoring force point of the rock ring. After confirming that the system water pressure has reached the set clamping back pressure threshold, the drill rod body 1 is lifted upward. Under the continuous upward pulling force of the drill bit, the concentric rock ring 24 has a relative downward tendency due to its own weight and the connection force of the bottom bedrock. This downward tendency drags the top clamping plate 1102 down the wedge-shaped inclined surface on the movable plate 1101. Utilizing the mechanical self-locking effect of the wedge-shaped inclined surface, the axial upward pulling force of the drill rig and the self-weight of the rock ring are converted into an inward squeezing radial clamping force. As the tension of the lifting sleeve frame continues to increase, the radial clamping force will cause the concentric rock ring 24, which is about to break, to rise at a constant speed.

[0034] During the slag unloading operation, the concentric rock ring 24 is placed on the ground, and the drill rod body 1 continues to move downward relative to the concentric rock ring 24 that has already been placed on the ground. At this time, the top clamping plate 1102 moves upward relative to the movable plate 1101. The movable plate 1101 is reset and retracted into the pipe wall of the drive hydraulic chamber 18 under the action of the rebound mechanism, thereby causing the top clamping plate 1102 to release the clamping of the concentric rock ring 24. The radial clamping assembly 11 retracts, and after clearing the bottom of the hole, the above-mentioned drilling and excavation cycle is repeated.

[0035] Example 3, based on Example 2, proposes specific implementation steps for a construction method of a water-cooled drilling system for vertical tunneling.

[0036] In one construction method, during step S2, when encountering a low-resistance area such as soft rock or a collapsed karst cave, the guide pipe 3 extends forward under the thrust of the first elastic component 402, and the sealing sleeve 4 connects with the grouting channel 7 inside the guide pipe 3. The consolidating grout in the grouting channel 7 is automatically injected into the soil layer 23. When encountering hard rock or soft rock and being compressed to the extreme state, causing the end face bearing capacity to exceed the spring preload threshold, the guide pipe 3 is pushed back until the sealing sleeve 4 and the grouting channel 7 inside the guide pipe 3 are misaligned and sealed, and the injection of consolidating grout stops. Specifically, during construction in water-bearing loose sand layers, if the central cutting tooth 6 penetrates into a cavity or extremely soft silt, the central cutting tooth 6 and the concentric cutting drill barrel 9 simultaneously contact the stratum. The guide pipe 3 and the drill rod body 1 do not have significant relative slippage during drilling in soft soil, and the grouting channel 7 and the grout discharge guide hole 16 remain connected before the sealing sleeve 401 is compressed to its limit. The pressurized fast-setting cement-based grout or chemical dual-liquid grout in the ground grouting pump is instantly ejected, spreading and penetrating into the surrounding cavities at a high flow rate. This replaces the mud and water inside the borehole and consolidates the surrounding soil, effectively preventing borehole instability and collapse. As the grout solidifies and the drill bit continues to apply downward pressure, the formation density gradually increases. When the central cutting tooth 6 contacts the solid bedrock surface, or when the high-strength solidified body formed by the injected grout below generates a reverse thrust on the end face exceeding the compressive strength threshold of the first elastic component 402, the guide pipe 3 is forcibly pushed upward and retracted. During this retraction, the grouting channel 7 slides into the closed blind zone and is completely sealed. The grout delivery can be instantly cut off without the need for instructions from surface personnel, seamlessly switching the function of the cutterhead assembly back to pure mechanical rock-breaking and cutting mode, avoiding grout waste and spillage that could contaminate the working face of the surrounding water-grinding teeth.

[0037] Example 4, based on Example 3, proposes specific implementation steps for a construction method of a water-cooled drilling system for vertical tunneling.

[0038] In one construction method, in step S3 above, after the high-pressure cooling water enters the cooling channel 15, it flows to the end face of the concentric cutting drill barrel 9 for slag removal and cooling. After the high-pressure cooling water enters the push channel 10, it pushes the radial clamping assembly 11 to radially clamp the cut independent concentric rock rings 24. Specifically, in soft soil drilling or conventional negative pressure low drilling pressure cutting mode, the side hole of the valve core 801 is connected to the first connecting hole 13, and a large flow of cooling water is directly sprayed through the cooling channel 15 to the root of the diamond cutting teeth at the bottom of the concentric cutting drill barrel 9. The high-speed water flow here forms a strong turbulent scouring effect, which carries away the generated high heat to prevent drill burn, and at the same time suspends and flushes the cut rock powder and mud, providing a hydrodynamic carrier for subsequent negative pressure suction or overflow discharge. When encountering hard rock and core extraction is required, the channel distribution valve 8 slides and reverses, the first connecting hole 13 is closed, causing the bottom cooling water path to be cut off, and the fluid accumulated in the system is introduced into the second connecting hole 14 and the push channel 10. At this point, the water flow changes from a cleaning medium to a hydraulic transmission medium, accumulating pressure in the closed pipe wall cavity, pushing the radial clamping assembly 11, which is attached to the pipe wall on one side and contacts the rock ring on the other side, to extend towards the center of the rock cylinder, providing a stable anchoring point for mechanical self-locking pull-out.

[0039] Example 5, based on Example 4, proposes specific implementation steps for a construction method of a water-cooled drilling system for vertical tunneling.

[0040] In one construction method, in step S4 above, after the radial clamping assembly 11 is pushed out by high-pressure cooling water to initially engage the rock ring, when the drill rod body 1 is lifted upward, the concentric rock ring 24 experiences a downward tendency due to the reaction force of its own weight and the top tension. This downward tendency causes the radial clamping assembly 11 to be subjected to a downward pulling force. Utilizing the friction force generated by the contact surface, the axial force is converted into an inward squeezing radial clamping force, thereby ensuring that the concentric rock ring 24 does not fall off during deep hole lifting. Specifically, at the moment when the ground equipment starts the lifting casing frame to forcefully lift the drill rod body 1, the concentric cutting drill barrel 9 moves upward as a whole. Because the bottom of the concentric rock ring 24 is still connected to the bedrock and its own mass is relatively large, the downward movement tendency causes the top clamping plate 1102 to be dragged downward by the friction of the rock surface, forcing it to overcome the supporting force of the second elastic component 1104 and slide down along the wedge-shaped inclined surface on the movable plate 1101. According to the principles of inclined plane mechanics, during the descent of the clamping plate 1102, it is inevitably subjected to a stronger radial horizontal expansion force guided by the inclined plane, wedging itself tightly between the outer wall of the concentric rock ring 24 and the inner wall of the drill barrel. As the ground lifting force continues to increase, the radial clamping force continues to amplify until it exceeds the tensile and flexural yield limit of the rock mass at the connection between the bottom of the concentric rock ring 24 and the bedrock, and is rigidly split and broken apart.

[0041] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A water-cooled drilling system for vertical excavation, comprising a drill rod body (1) for excavating a soil layer (23), the drill rod body (1) comprising a power drive assembly disposed on its upper part for driving its rotation, and a cutterhead assembly disposed below its inner cavity, characterized in that: The cutterhead assembly includes a dual-channel rotary joint (2) that is independently connected to high-pressure cooling water and solidification slurry, and a grouting sensing component and a concentric circular drill assembly that are coaxially sleeved from the inside to the outside. The grouting sensing component includes a guide pipe (3) and an elastic sealing kit (4). The sealing kit (4) is connected to the bottom of the guide pipe (3). The bottom center of the drill rod body (1) is provided with a through hole (5) for the guide pipe (3) to pass through axially. The end of the guide pipe (3) is provided with a central cutting tooth (6). The lower end of the dual-channel rotary joint (2) is connected to the grouting channel (7) inside the guide pipe (3). The guide pipe (3) is axially controlled by the drilling pressure and generates relative movement with the drill rod body (1), and cooperates with the sealing kit (4) to adaptively open and close the grouting channel (7). The concentric circular drill assembly includes a concentric cutting drill barrel (9) and a flow channel distribution valve (8) disposed in the drill rod body (1) for distributing the flow direction of the high-pressure cooling water. The concentric cutting drill barrel (9) integrates a cooling flow channel (15) and a push flow channel (10), and a radial clamping assembly (11) driven by the fluid in the push flow channel (10) is arrayed on the inner side wall of its lower end. The flow channel distribution valve (8) is linked and cooperates with the guide pipe (3). The cutterhead assembly is configured to have two linkage states: when the central cutting tooth (6) drills into the soft soil area, the grouting channel (7) is connected, and the channel distribution valve (8) leads the cooling water to the outside of the concentric cutting drill barrel (9) for slag discharge cooling; when the central cutting tooth (6) drills into the hard rock area or cannot overcome the formation resistance, the grouting channel (7) is closed, and the channel distribution valve (8) introduces the cooling water into the push channel (10) to drive the radial clamping assembly (11) to push out the clamping concentric rock ring (24).

2. The water-cooled drilling system for vertical tunneling according to claim 1, characterized in that: The concentric cutting drill barrel (9) is fixed below the outer end of the drill rod body (1). The concentric cutting drill barrel (9) is composed of a double-layer pipe wall. The push flow channel (10) and the cooling flow channel (15) are independently located inside the double-layer pipe wall. The flow channel distribution valve (8) includes a valve core (801) and a valve sleeve (802) with an axial sliding assembly gap. The valve core (801) is sleeved and fixed on the guide pipe (3). The side wall of the valve core (801) is provided with a side hole that communicates with the water inlet flow channel (12) of the inner cavity of the guide pipe (3). The valve sleeve (802) is provided with a vertical first connecting hole (13) and a second connecting hole (14). The first connecting hole (13) is guided to the end face of the concentric cutting drill barrel (9) through the cooling flow channel (15). The second connecting hole (14) is connected to the push flow channel (10).

3. A water-cooled drilling system for vertical tunneling according to claim 2, characterized in that: The sealing kit (4) includes a sealing sleeve (401), a first elastic component (402), and a limiting ring (403) disposed at the lower end of the outer wall of the guide pipe (3). The first elastic component (402) is sleeved on the guide pipe (3) and abuts against the limiting ring (403) and the drill rod body (1). The sealing sleeve (401) is disposed below the through hole (5) and the guide pipe (3) fits and passes through its inner cavity. The side wall of the sealing sleeve (401) is provided with a slurry discharge guide hole (16).

4. A water-cooled drilling system for vertical tunneling according to claim 3, characterized in that: When the first elastic component (402) is in a state of natural extension or not under extreme compression, the grouting channel (7) is connected to the grout discharge guide hole (16), and the side hole of the valve core (801) is connected to the first connecting hole (13). When the first elastic component (402) is at its compression limit, the grouting channel (7) and the grout discharge guide hole (16) are misaligned and closed, and the side hole of the valve core (801) is connected to the second connecting hole (14).

5. A water-cooled drilling system for vertical tunneling according to claim 4, characterized in that: The initial preload and stiffness coefficient of the first elastic component (402) are configured to be greater than the ultimate penetration resistance of conventional soft soil and silt strata to the central cutting tooth (6), so that the first elastic component (402) remains extended when drilling in soft soil, and less than the end face bearing capacity of hard rock or highly dense soil strata (23) to the central cutting tooth (6), so that the first elastic component (402) is forcibly compressed when touching hard strata.

6. A water-cooled drilling system for vertical tunneling according to claim 5, characterized in that: The upper end of the guide pipe (3) is connected to the double-channel rotary joint (2) through the sleeve telescopic pipe (17). The grouting channel (7) and the water inlet channel (12) are respectively connected to the external solidification grout and high-pressure cooling water through independent sealed pipelines.

7. A water-cooled drilling system for vertical tunneling according to claim 1, characterized in that: The bottom of the push flow channel (10) is connected to the side of the center cutting tooth (6) with a driving hydraulic cavity (18). The radial clamping assembly (11) is horizontally slidably connected to the driving hydraulic cavity (18) through the transverse guide groove (19). One end of the driving hydraulic cavity (18) is connected to the push flow channel (10), and the other end of the driving hydraulic cavity (18) is connected to the outside. The radial clamping assembly (11) vertically closes the driving hydraulic cavity (18). Both ends of the guide groove (19) are provided with limit clips (20).

8. A water-cooled drilling system for vertical tunneling according to claim 7, characterized in that: The radial clamping assembly (11) includes a movable plate (1101) and a top clamping plate (1102). The movable plate (1101) and the top clamping plate (1102) are slidably engaged by opposing wedge-shaped inclined surfaces. A limiting groove (1103) is provided on the movable plate (1101). A second elastic component (1104) is provided in the limiting groove (1103). A limiting top block (1105) is provided on the side of the top clamping plate (1102) facing the movable plate (1101) and embedded in the limiting groove (1103). The second elastic component (1104) is located below the limiting top block (1105) to push the top clamping plate (1102) to move upward relative to the movable plate (1101).

9. A water-cooled drilling system for vertical tunneling according to claim 8, characterized in that: The top clamping plate (1102) is provided with several anti-slip hard teeth (21) on the side facing the central cutting tooth (6) for biting the rock. The upper end of the movable plate (1101) is also provided with a horizontal drainage cavity (22) for pressure relief. The horizontal drainage cavity (22) is connected to the outside when the second elastic component (1104) is compressed to the limit position.

10. A water-cooled drilling system for vertical tunneling according to claim 1, characterized in that: It also includes a detachable platform, a lifting casing frame and a split hydraulic power mechanism installed at the wellhead on the ground. The detachable platform spans across the wellhead, and the lifting casing frame slides up and down along the vertical guide rail of the detachable platform. The power drive assembly is installed on the lifting casing frame and driven by the split hydraulic power mechanism. The lifting action of the lifting casing frame applies drilling pressure or lifting pull to the drill pipe body (1) below.

11. A construction method based on the water-cooled drilling system for vertical tunneling as described in any one of claims 1-10, characterized in that, Includes the following steps: S1: Assemble the modular detachable platform and install the drill pipe body (1) above the wellhead, and connect the external high-pressure cooling water and solidification slurry to the dual-channel rotary joint (2) at the same time, and lower the drill pipe body (1). S2: During the lowering process, the power drive component applies drilling pressure downwards, and the concentric cutting drill barrel (9) and the central cutting tooth (6) contact the stratum. Based on the hardness of the stratum rock and soil, the magnitude of the reaction force on the end face of the central cutting tooth (6) causes the guide pipe (3) to generate relative axial displacement, thereby automatically controlling the opening and closing of the grouting channel (7). S3: At the same time, the guide pipe (3) drives the flow distribution valve (8) to generate relative displacement according to the difference in hardness of the soil and rock in the stratum, and automatically controls the high-pressure cooling water to enter the cooling flow channel (15) or push the flow channel (10). S4: After cutting to the predetermined depth or encountering resistance that prevents further advancement, the drill rod body (1) is raised. At this time, the radial clamping assembly (11) abuts against the concentric rock ring (24), and the drill rod body (1) is used to lift it from the bottom bedrock. The friction between the abutting surface and the concentric rock ring (24) is used to hold and drive the concentric rock ring (24) to rise until it is pulled out to the ground for slag removal, and the excavation is repeated.

12. The construction method according to claim 11, characterized in that: In step S2 above, when the guide pipe (3) is pushed forward by the elastic sealing kit (4) when it touches the soft rock or the low resistance area of ​​the cave collapse, the sealing kit (4) connects with the grouting channel (7) inside the guide pipe (3), and the consolidation grout in the grouting channel (7) is automatically injected into the soil layer (23); when the hard rock or soft rock is pressed to the extreme state of compaction, causing the end face bearing capacity to exceed the spring preload threshold, the guide pipe (3) is pushed back until the sealing kit (4) and the grouting channel (7) inside the guide pipe (3) are misaligned and sealed, and the injection of consolidation grout stops.

13. The construction method according to claim 11, characterized in that: In step S3 above, when the high-pressure cooling water enters the cooling channel (15), it flows to the end face of the concentric cutting drill barrel (9) to discharge slag and cool down; when the high-pressure cooling water enters the pushing channel (10), the high-pressure cooling water pushes the radial clamping assembly (11) to radially clamp the cut independent concentric rock ring (24).

14. The construction method according to claim 11, characterized in that: In step S4 above, the clamping force process of the rising drill rod body (1) pulling out the concentric rock ring (24) is as follows: when the radial clamping component (11) is pushed out by the high-pressure cooling water to initially bite the rock ring, when the drill rod body (1) is lifted upward, the concentric rock ring (24) will have a downward tendency due to its own weight. This downward tendency will cause the radial clamping component (11) to be subjected to a downward pulling force. By using the friction force generated by the contact surface, the axial gravity is converted into an inward squeezing radial clamping force, thereby ensuring that the concentric rock ring (24) does not fall off during the deep hole lifting process.

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